misc: mic/scif: fix copy-paste error in scif_create_remote_lookup

misc: mic/scif: fix copy-paste error in scif_create_remote_lookup

gcc '-Wunused-but-set-variable' warning:

drivers/misc/mic/scif/scif_rma.c: In function 'scif_create_remote_lookup':
drivers/misc/mic/scif/scif_rma.c:373:25: warning:
 variable 'vmalloc_num_pages' set but not used [-Wunused-but-set-variable]

'vmalloc_num_pages' should be used to determine if the address is
within the vmalloc range.

Fixes: ba612aa8b487 ("misc: mic: SCIF memory registration and unregistration")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>